Nonwoven separator for a nickel-metal hydride battery

Abstract

The preferred embodiment is to a battery separator for a nickel metal hydride (NiMH) battery. The separator includes a wettable, resilient nonwoven web having two spunbond layers sandwiching a melt blown layer. The web has a puncture strength of greater than 6 newtons, a tensile strength of greater than 200 newtons/meter, and an average pore size of less than 20 microns.

1 . A battery separator comprising: 
 a wettable, resilient nonwoven web including at least one spunbond layer and at least one melt-blown layer;    said web having a puncture strength of greater than 6 newtons, a tensile strength of greater than 200 newtons/meter, and an average pore size of less than 20 microns.    
     
     
         2 . A battery separator comprising: 
 a wettable, resilient nonwoven web including two spunbond layers sandwiching a melt-blown layer;    said web having a puncture strength of greater than 6 newtons, a tensile strength of greater than 200 newtons/meter, and an average pore size of less than 20 microns.    
     
     
         3 . In a nickel-metal hydride battery having a separator, said separator comprising: 
 a wettable, resilient nonwoven web including two spunbond layers sandwiching a melt-blown layer;    said web having a puncture strength of greater than 6 newtons, a tensile strength of greater than 200 newtons/meter, and an average pore size of less than 20 microns.    
     
     
         4 . The separator according to  claim 2  or  3  wherein said resilient web has a resiliency of at least 40%.  
     
     
         5 . The separator according to  claim 2  or  3  wherein said resilient web has a resiliency of at least 60%.  
     
     
         6 . The separator according to claims  2  or  3  wherein said puncture strength being greater than 9 newtons.  
     
     
         7 . The separator according to claims  2  or  3  wherein said tensile strength being greater than 600 newtons/m.  
     
     
         8 . The separator according to claims  2  or  3  wherein said average pore size ranging from 5 to 15 microns.  
     
     
         9 . The separator according to claims  2  or  3  wherein said web further comprises two spunbond layers sandwiching two melt-blown layers.  
     
     
         10 . The separator according to claims  2  or  3  wherein said web being wettable by a treatment selected from the group consisting of: coating with a surfactant, coating with a polymer, surface activating, surface roughing, blending another polymer into the web, and combinations thereof.  
     
     
         11 . A battery comprising: 
 a nickel electrode;    a metal hydride electrode;    a separator located between said electrodes, said separator comprising a wettable, resilient nonwoven web including two spunbond layers sandwiching a melt-blown layer; and    an aqueous electrolyte, said electrolyte in fluid communication with said electrodes via said separator.    
     
     
         12 . The battery of  claim 11  wherein said web having a puncture strength of greater than 6 newtons, a tensile strength of greater than 200 newtons/meter, and an average pore size of less than 20 microns.  
     
     
         13 . The separator according to  claim 12  wherein said resilient web has a resiliency of at least 40%.  
     
     
         14 . The separator according to  claim 12  wherein said resilient web has a resiliency of at least 60%.  
     
     
         15 . The separator according to  claim 12  wherein aid puncture strength being greater than 9 newtons.  
     
     
         16 . The separator according to  claim 12  wherein said tensile strength being greater than 600 newtons/m.  
     
     
         17 . The separator according to  claim 12  wherein said average pore size ranging from 5 to 15 microns.  
     
     
         18 . The separator according to  claim 12  wherein said web further comprises two spunbond layers sandwiching two melt-blown layers.  
     
     
         19 . The separator according to  claim 12  wherein said web being wettable by a treatment selected from the group consisting of coating with a surfactant, coating with a polymer, surface activating, surface roughing, blending another polymer into the web, and combinations thereof.